1. Field of the Invention
This invention relates to images. In particular, an exemplary aspect of this invention relates to quality control for image compression.
2. Description of Related Art
With the dependence on multimedia technologies becoming greater exponentially, image compression techniques need to correspondingly increase in performance. The JPEG2000 standard is intended to provide rate distortion and subjective image quality performance superior to existing standards, and to also provide features and functionalities that current standards address only partially or do not address at all. The JPEG2000 standard is designed to address requirements of a diversity of applications, for example, images, internet multimedia, color facsimile, printing, color printing, scanning, digital photography, remote sensing, mobile applications, medical imagery, digital libraries, and e-commerce, just to name a few.
The JPEG2000 standard is the new image compression standard created by ISO/IEC JTC1 SC29 Working Group 1, also known as the Joint Photographic Experts Group (JPEG). Part 1 of the JPEG2000 standard, which is incorporated herein by reference in its entirety, addresses the compression of still images.
As is common with the majority of compression standards, Part 1 of the JPEG2000 standard is a decoder standard. The standard addresses the syntax of the compressed code stream and the required behavior of the decoder, i.e., exactly how the decoder is to decode a compliant coded stream. Although the encoding process is implicitly dictated by the standard, not all encoding details are specified by the standard. In fact, there are several decisions and options that are left up to the encoder. A simple example is the number of wavelet transform levels, which is strictly an encoder determined option. Specifically, the number of transform levels is not dictated by the standard, only a range of allowable values, i.e., from 0 to 32, is provided.